Spark-plug.



J. w. BAIRD. SPARK PLUG.

APPLICATION Fll ED JAN-24.1916.

Patented July 11, 1916.

JOHN W. BAIRD, CHICAGO, ILLINOIS.

sranir-rnus.

Continuation in part of application Serial No. 57,460, filed October 23, 1915.

Serial No. 73,982.

My invention relates to improvements in spark plugs, the present application being in part a division of my pending application Serial No. 57,460, filed October 23rd,19l5 for spark plugs.

The object of this invention is the production of a spark plug which will be so constructed as to practically eliminate the pos sibility of fouling when the plug is in use.

A further object is the production of a spark plug which may be economically manufactured and which will be highly eliicient in operation.

and arrangements of parts hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawing forming a part of this specification, and in which Figure 1 is a central longitudinal section of a spark plug embodying the invention, Fig. 2 is a bottom plan view thereof, Fig. 3 is a central longitudinal section through the lower portion of a spark plug of a slightly modified form, and Fig. t is a bottom plan view of Fig. 3. I

The form of the construction as illustrated in Figs. 1 and 2 comprises a spark plug coni ng of an outer tubular body 1 which forms one pole or the plug and an inner slender rod 2 which is arranged centrally in the member 1 and which forms the other pole of the plug. The parts 1 and 2 are connected together and insulated from each other in the usual manner.

- Provided at the lower end of the inner pole member 2 is an. elongated bar 3 secured. to the member 2 by means of a transversel' extending in 4c so as to permit of rocking movement of said ban The pin 4: passes through ears 5 which project upwardly irom the longitudinal edges of bar 3 midway the ends of the latter. Opposite sides of incmher 2 are tened as seen to accommodate the ears 5. he member 3 is thus permitted free rocking movement within a fixed range, the movement thus afforded being deter- Specification of Letters Patent.

Patented .nn ii, min. This application filed January mined by the corners 6 at the lower end of the pole member 2 which are adapted for engagement against the upper side oi bar 3 -in order to permit rocking movement thereof, as shown in dotted lines in Fig. l. The arrangement is such that the bar 3 will be prevented from contacting with thp pole member 1 of the spark plug a gap being always formed between the ends of said bar and the lower or inner edge of the'member 1 for the jumping of the spark.

With this construction it will be seen that during explosion in the engine cylinder or upon rushing of the gases from the cylinderduring scavenging of the latter the dis turbance in the cylinder will have the eiiect of vibrating the member 3 so as to shake any soot, carbon, or other reign matter therefrom in order to prevent fouling in the operation of the spark plug. The invention consists in the combinations In the form shown in Figs. 3 and 4 the lower end of the pole member 2 projects througha slot 7 provided in the oscillatory member 3 so that the ends of said slot constitute stops adapted for engagement against the opposite sides of said pole member in limiting the amplitude of oscillation of the member 3 as will be readily understood. Also in this form one end of the member 3 is reduced in width, thereby unbalancing said member, and whereby the opposite end of the same will normally be in lowered posi-- tion, as shown in Fig. 3, b ecausc of gravity. The reduction of one end of said member 3 also reduces the area of the under side thereof so that in the operation of the engine in which theplug is employed, the opposite end of said member 3 will be unevenly affected by the pressure in the cylinder or the rapidly moving gases passing the spark plug, with the result of insuring the desired vibration of said member 3'. The difierence in weight of the opposite ends of the bar also aids in obtaining this result inasmuch as the heavier or larger end of the member 3 will be elerated by the pressure of the gases in the cylinder and lowered by gravity.

While I have illustrated and described the preferred forms ofconstructien for carrying my invention into efiect, these are capable of variation and modification without departing from the spirit of the invention. I therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of, such variations and modimounted intermediate its ends upon one of said poles so that in the oscillation of said fications as come within the scope of the appended claims.

Having described my invention what I claim as new and desire to secure by Letters Patent is:

1. A spark plug for explosion engines comprising two poles; a member rockingly mounted intermediate its ends upon one. of said poles so that in the oscillation of said member the ends thereof will move toward and from the other pole, one end of said member being heavier than the other; and means for limiting oscillatory movement of said member to prevent contact thereof with said last mentioned pole, substantially as described.

2. A spark plug for explosion engines comprising two poles; a member rockingly member, the ends thereof will move toward and from the other pole, the under side of one end of said member disposed parallel with the axis of said member being of less area than that of the corresponding side of the other end; and means for limitingoscillatory movement of said member to prevent contact thereof with said last mentioned pole, substantially as described.

3. A spark plug for explosion engines comprising an outer tubular body forming one pole of the plug; an inner .centrally positioned, longitudinally extending member arranged in said body and forming the other pole of the plug; a transversely extending elongated member mounted intermediate its ends upon the inner end of said last mentioned member for free vertical movement about a transverseaxis whereby, in the oscillation of said member, the ends thereof will 'move toward and from opposite sides of said tubular member and means for limiting os-- illatory movement of said elongated member to pre ent contact thereof with the tubucomprising an outer tubular body forming 1 one pole of the plug; an inner centrally positioned longitudinally extending member arranged in said body and forming the other pole of the plug; a transversely extending elongated member mounted intermediate its ends upon the inner end of said last mentioned member for free vertical movement about a transverse axis, the under side of one end of said member disposed parallel with the axis ofsaid member being of less area than that of the corresponding side of the other end; and means for limiting oscillatory movement of said member to prevent contact thereof with the tubular pole member, substantially as described.

' 5. A spark plug for explosion engines comprising an outer tubular body forming one pole of the plug; an inner centrally positioned longitudinally extending member arranged in said body and forming the other pole of the plug; a transversely extending bar mounted centrally upon the inner end of said member for free oscillatory movement about a transverse axis; and shoulders at the inner end of said central member adapted for engagement with the upper side of said bar at opposite sides of the pivot thereof for limiting oscillatory movement of said bar to prevent contact thereof with said tubular pole member, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

. JOHN W. BAIRD. Witnesses:

JosrIUA R. H. Po'r'rs, Conn F. Scnmnnn. 

